1. Field of the Invention
The invention relates to the delivery of drugs to animals, and more particularly to devices for enabling the delivery of drugs or medicaments to animals for pulmonary or nasal absorption via the mouth and or nose.
2. Summary of the Related Art
In many circumstances, it is desired to deliver a drug or a medicament to an animal, and in particular a mammal, such as a human, a dog or a horse, for pulmonary or nasal absorption. Direct application, such as by a spray or aerosol delivery device, or a dry powder delivery device, is difficult due to movements of the animal. To enable such application of medicaments in the prior art, an elongated, generally cup-shaped xe2x80x9cmaskxe2x80x9d is often provided, having a relatively large open base end for fitment over an animal""s nostril or muzzle and having a medicament administration port opposite that base end. Typically the mask is made out of a semi-rigid material (eg., sheet polycarbonate) and is provided in various sizes for use with different sized animals.
In use in the prior art, an appropriate sized mask is selected, and the open base end is positioned over the animal""s nostril or muzzle, preferably with a friction fit at the open base end. The size of the open end is such that at least a rough seal is established between the open end of the mask and the animal""s nostril or muzzle. When the mask is so positioned, medicament is delivered at the medicament administrative port, for example by spray, aerosol delivery device, or dry powder medicament delivery device, either breath-activated or user-driven. As the animal breathes, the medicament is drawn into one (or both) nostril(s), or in the mouth and into the lungs or the nasal passages.
This mask-type administration of medicaments has proven to be a generally effective method for medicament delivery. However, there are inconveniences and difficulties associated with the prior art masks. More particularly, because of the semi-rigid structure of such masks, the masks are bulky and take up significant volume when carried around by a veterinarian, or other provider. Moreover, the semi-rigid structure of such masks makes it necessary to provide a set of various sized masks in order to be able to provide masks for correspondingly sized animals. In addition, because of the xe2x80x9croughxe2x80x9d nature of the seal provided by the semi-rigid material of the conventional masks, many of those masks are provided with tubes, and the like, for insertion deep into the animal""s nostrils. The latter type of mask is particularly difficult to clean making it difficult to use it for more than one animal at a time without cross-contamination.
Therefore, there is a need for an improved mask for delivering drugs to animals for pulmonary or nasal absorption via the mouth and/or nose. Such improved mask should be (a) collapsible to a relatively small volume form for ease and convenience in transport; (b) adaptable for use with different sized animals; and (c) easily cleaned, to permit re-use with the same or different animals.
The present invention is a drug or medicament, delivery device for fitment to the appropriate portion of the head of the animal such as the front of the head or over one nostril for the effective delivery of drugs or medicaments, for pulmonary or nasal absorption. The device is in the form of a mask. The mask is collapsible to permit use in a full or partially open state, and to permit easy and convenient transport in a collapsed or closed state. In a preferred form, the mask of the invention is particularly adaptable to accommodate size variation in animals.
The drug delivery mask of the invention is adapted for removable fixture to the appropriate portion of the head of the animal such as the front of the head (i.e, a portion of the face), the nostril or the muzzle. The mask includes two or more telescopable sections, which are coupled together. Each section includes a relatively inflexible ring defining an associated first contour, and each has a relatively flexible skirt extending from its ring to a distal edge. The distal edge of the skirt defines an associated second contour. The rings of the mask are nestable, forming a succession of monotonically decreasing sized rings from a largest ring to a smallest ring. Preferably, each ring fits inside the next larger ring in the succession, although in some forms two adjacent rings in the succession may be same size, and may not nest with each other. The second contour of a skirt of each ring in the succession, is substantially the same as, and is joined to, the first contour of the next ring of the succession. The various joined sections may be formed (such as by molding) as a unitary structure.
The present invention is intended for use with any animal which may experience the benefits of the invention. Foremost among such animals are those which are difficult to control or cannot be made to cooperate in the delivery of drugs or medicaments via conventional delivery devices. Hence the term xe2x80x9canimalxe2x80x9d is used to designate patients such as infants, children, physically or mentally disabled patients, as well as any other animal (e.g., a dog, a cat or a horse).
An airborne medicament interface adapter extends from the skirt of the smallest ring. The medicament interface adapter is adapted to couple that skirt to a medicament dispenser. Preferably, the medicament dispension is breath-activated but may be user (e.g., care giver) actuated. The medicament dispenser may be in the form of a dry powder medicament dispenser, or in aerosol dispenser. Alternatively, a user-actuated spray dispenser may be used.
The mask also includes an animal interface adapter extending from the largest ring. The animal interface adapter is adapted to provide a substantial (although not necessarily complete) pneumatic seal between the animal interface adapter and the appropriate portion of the head of the animal (e.g., the front of the head of a small child, the nostril or the muzzle of any animal such as cats, dogs or horses). By way of example, the animal interface adapter may be in the form of a thin or tapered flexible sheet, which when pressed against the area around the appropriate portion of the head, forms at least a rough seal. As a further example, the animal interface adapter may be in the form of a stretchable, nominally conic-frustrum shaped elastic sheet, extending from the largest ring. In the elastic form, the sheet may be stretched as the largest ring is moved over the nostril or muzzle of the animal. In some forms, an elastic or otherwise adjustable strap extends from the animal interface adapter, where the strap may be placed around the back of an animal""s head to secure the mask in place.
In a preferred form of the inventions, the sections of the mask are formed by molding as a unitary structure, made from one of the group consisting of a thermoplastic elastomer, high density polyethylene, low density polyethylene, polypropylene and silicone rubber. One of skill will appreciate that any material or method available in the art can be utilized in carrying out the invention. However, preferred materials methods are described. Materials, reagents and the like to which reference is made in the following description and examples are obtainable from commercial sources, unless otherwise noted.
The rings may be circular, elliptical or some other closed shape. By way of example, the respective rings may have a C-shaped cross-section, to impart a relatively inflexible characteristic, with its associated skirt extending from one end of the C and the distal edge of the skirt from the next ring being joined to the other end of the C. The skirts may be a material to impart a relatively flexible characteristic. Various dimensions and geometries may be used in keeping with the invention.